Project Summary There is a need to advance oral dietary supplement research to include development of microbial communities that support colon health and metabolism by reducing colon inflammation. This approach should not be confused with traditional approaches that have combined microbes into a supplement, and notably that the strains did not originate as a microbial community. Preliminary data support that oral delivery of a set of human stool microbes to mice conferred protection against colon inflammation and prevention of colon cancer. The microbial communities that were delivered orally to mice were derived from people that consumed a rice bran rich diet for one month. The parent R01 award is elucidating mechanisms by which a rice bran diet modified the human stool microbiome in a manner that provided protection from colon carcinogenesis. This supplement award proposes to functionally characterize the microbial community that is being delivered as an oral inoculum and will advance the field of microbial based dietary supplements using computational, integrated functional analysis. In this one- year supplement award period, we propose to perform a comprehensive meta-transcriptomic and metaproteomic investigation using an innovative workflow for functional characterization of colon health promoting microbial consortia. This is considered essential prior to development and use as microbial consortia-based dietary supplements. We hypothesize that human stool microbial communities that reduced colon inflammation can be safety developed when analyzed for functional health benefits as a microbial consortia. We will use stool microbial communities that were already collected from 5 females and 5 males before and after completing dietary intervention. The oral delivery of stool microbial consortia to mice were selected for use in this project based on functional efficacy. Employing metatranscriptomics to profile transcriptionally active genes in the microbial inoculum and therefore metabolically active microbes will be correlated with functional effects on the colon. We will also complete metaproteomics to understand what proteins/enzyme functions are actively produced and by which microbes; a traceability that extends beyond single microbial contribution to ascertain microbial community function. The application and integration of multiple meta-omics is essential to provide a complete mechanistic understanding of the candidate oral microbial consortium. This project will also develop a computational workflow for functional metabolic network mapping of each microbial consortia that will support future testing as an oral dietary supplement.